Abstract: The Bitcoin network of decentralized payment transactions has attracted a lot of attention from both Internet users and researchers in recent years. Bitcoin utilizes a peer-to-peer network to issue anonymous payment transactions between different users. In the currently used Bitcoin clients, the full transaction history is available at each node of the network to prevent double spending without the need for a central authority, forming a valuable source for empirical research on network structure, network dynamics, and the implied anonymity challenges, as well as guidance on the future evolution of complex payment systems. We found dynamical effects of which some increase anonymity while others decrease it. Most importantly, several parameters of the Bitcoin transaction graph seem to have become stationary over the last 12–18 months. We discuss the implications.
Abstract: Emergency planners, first responders and relief workers increasingly rely on computational and communication systems that support all aspects of emergency management, from mitigation and preparedness to response and recovery. Failure of these systems, whether accidental or because of malicious action, can have severe implications for emergency management. Accidental failures have been extensively documented in the past and significant effort has been put into the development and introduction of more resilient technologies. At the same time researchers have been raising concerns about the potential of cyber attacks to cause physical disasters or to maximise the impact of one by intentionally impeding the work of the emergency services. Here, we provide a review of current research on the cyber threats to communication, sensing, information management and vehicular technologies used in emergency management. We emphasise on open issues for research, which are the cyber threats that have the potential to affect emergency management severely and for which solutions have not yet been proposed in the literature.
Abstract: Norwegian authorities’ policy aims at securing an information society for all, emphasizing the importance of accessible and usable Information and Communication Technology (ICT) for everyone. While the body of research on young people’s use of ICT is quite comprehensive, research addressing digital differentiation in young people with disabilities’ use of ICT is still in its early days. This article investigates how young people with disabilities’ use, or non-use, of assistive ICT creates digital differentiations. The investigation elaborates on how the anticipations and stereotypes of disability establish an authoritative definition of assistive ICT, and the consequence this creates for the use of the Web by young people with disabilities. The object of the article is to provide enhanced insight into the field of technology and disability by illuminating how assistive ICT sometimes eliminates and sometimes reproduces stereotypes and digital differentiations. The investigation draws on a qualitative interview study with 23 young Norwegians with disabilities, aged 15–20 years. I draw on a theoretical perspective to analyze the findings of the study, which employs the concept of identity multiplicity. The article’s closing discussion expands on technology’s significance in young people’s negotiations of impairment and of perceptions of disability
Abstract: A highly efficient self-provisioning interference management scheme is derived for 3G Home Node-Bs (HNB). The proposed scheme comprises self-adjustment of the HNB transmission parameters to meet the targeted QoS (quality of service) requirements in terms of downlink and uplink guaranteed minimum throughput and coverage. This objective is achieved by means of an autonomous HNB solution, where the transmit power of pilot and data are adjusted separately, while also controlling the uplink interference pollution towards the macro-layer. The proposed scheme is evaluated by means of extensive system level simulations and the results show significant performance improvements in terms of user throughput outage probability, power efficiency, femtocell coverage, and impact on macro-layer performance as compared to prior art baseline techniques. The paper is concluded by also showing corresponding measurements from live 3G high-speed packet access (HSPA) HNB field-trials, confirming the validity of major simulation results and assumptions.
Abstract: This article presents and explains a methodology based on cryptanalytic and reverse engineering techniques that can be employed to quickly recover information from encrypted files generated by malware. The objective of the methodology is to minimize the effort with static and dynamic analysis, by using cryptanalysis and related knowledge as much as possible. In order to illustrate how it works, we present three case studies, taken from a big Brazilian company that was victimized by directed attacks focused on stealing information from a special purpose hardware they use in their environment.
Abstract: An attractive advantage of mobile networks is that their users can gain easy access to different services. In some cases, equivalent services could be fulfilled by different providers, which brings the question of how to rationally select the best provider among all possibilities. In this paper, we investigate an answer to this question from both quality-of-service (QoS) and energy perspectives by formulating an optimisation problem. We illustrate the theoretical results with examples from experimental measurements of the resulting energy and performance.
